Touch sensor panel and method for fabricating the same

ABSTRACT

The present invention provides a touch sensor panel and a fabrication method thereof, in which metal wires for forming a metal mesh are subject to patterning to have symmetrical components being in correlation with each other on the basis of x and y axes, thereby improving visibility. In the touch sensor panel and the fabrication method thereof, the metal wires consist of continuous unit wires in which a unit wire and another unit wire crossing with the unit wire have symmetrical components being in correlation with each other and the size of the symmetrical components is determined based on the line width of the unit wires.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. application Ser.No. 15/512,262, filed Mar. 17, 2017, which is a National Stage ofInternational Application No. PCT/KR2015/009650 filed Sep. 15, 2015,claiming priority based on Korean Patent Application No.10-2014-0125016, filed Sep. 19, 2014, the contents of all of which areincorporated herein by reference in their entirety.

TECHNICAL FIELD

The present invention relates to a touch panel, and more particularly,to a touch sensor panel and a fabrication method thereof, in which metalwires for forming a metal mesh are subject to patterning to havesymmetrical components being in correlation with each other on the basisof x and y axes, thereby improving visibility.

BACKGROUND ART

A touch panel, which is an input/output means for detecting a touchposition of a user on a display screen and receiving information on thedetected touch position to perform an overall control of an electronicdevice including a display screen control, is a device which recognizestouch as an input signal when an object such as a finger or a touch penis touched on the screen.

The touch input device has been frequently mounted on a mobile devicesuch as a mobile phone, a personal digital assistant (PDA), and aportable multimedia player (PMP) in recent years. In addition, the touchinput device is used throughout overall industries, such as anavigation, a netbook, a notebook, a digital information device (DID), adesktop computer using an operating system that supports touch input, aninternet protocol TV (IPTV), a state-of-the-art fighter, a tank, and anarmored vehicle.

The touch panel is designed to be added on or embedded in a displaydevice such as a liquid crystal display (LCD), a plasma display panel(PDP), an organic light emitting diode (OLED), or an active matrixorganic light emitting diode (AMOLED).

The touch panel is optically transmissive and includes detecting unitsemploying a conductive material.

The detecting units are formed in repetitive patterns in order torecognize the position of an input signal on the touch sensor panel. Inthis case, there is a problem that as detecting layers including thedetecting units are laminated in parallel, the patterns overlap eachother and therefore a moire phenomenon occurs due to interferencebetween the patterns.

There are proposed methods in which, when patterns constitutingdetecting electrodes overlap each other due to the stack of detectingsubstrates or the stack of the detecting substrate and an image displaypanel, torsion based on a predetermined angle is applied between thepatterns to prevent the occurrence of a moire pattern, thereby solving aproblem that visibility is deteriorated due to the moire pattern.

As another method for improving visibility deterioration due todiffraction, refraction, diffused reflection, moiré pattern and the likeby the mesh patterns constituting detecting electrodes, Korean PatentNo. 10-1111564 discloses a sensor for a capacitive touch panel,including honeycomb mesh patterns and a capacitive touch panel, in whichmesh patterns comprising honeycomb patterns and diamond patterns areused to improve visibility.

However, such a mesh pattern structure formed by continuously repeatedhoneycomb patterns and diamond patterns may have a reduced transmittancedue to the overlap of the patterns, and it has a difficulty in massproduction.

DISCLOSURE OF INVENTION Technical Problem

The present invention is to solve the problems of the mesh patternstructure in the prior touch panel, and therefore, an object of thepresent invention is to provide a touch sensor panel and a fabricationmethod thereof, in which metal wires for forming a metal mesh aresubject to patterning to have symmetrical components being incorrelation with each other on the basis of x and y axes, therebyimproving visibility.

Another object of the present invention is to provide a touch sensorpanel and a fabrication method thereof, in which metal wires for forminga metal mesh are subject to patterning to have a combination of severalsymmetrical components being in correlation with each other on the basisof x and y axes, thereby improving visibility.

Still another object of the present invention is to provide a touchsensor panel and a fabrication method thereof, in which tetragonal topolygonal patterns are freely formed by patterning that implements acombination of several symmetrical components, thereby improvingvisibility without limitation to pattern forms.

Still another object of the present invention is to provide a touchsensor panel and a fabrication method thereof, in which metal wires havedifferent angles formed by one of them and the x or y axis, based ontheir line width greater or less than the reference line width value,thereby forming a metal mesh having an optimum angle capable ofpreventing the occurrence of a moire pattern.

The objects of the present invention are not limited to theaforementioned objects, and other objects thereof will be understandableby those skilled in the art from the following descriptions.

Technical Solution

According to an aspect of the present invention, there is provided atouch sensor panel having electrode patterns in which continuous unitmeshes consisting of conductive unit wires are arranged, wherein twounit wires connected to a vertex of the unit mesh form an anglesatisfying the following equation with the x-axis or the y-axis:|Θ₁|=|Θ₂|

wherein,

Θ₁ is an angle formed by any one of two unit wires and the x-axis, and

Θ₂ is an angle formed by the other unit wire and the x-axis or they-axis.

The above equation is applied for all vertices constituting the unitmesh.

The angle (Θ, Θ=|Θ₁|=|Θ₂|) formed by each of two unit wires and thex-axis or the y-axis may satisfy 18°<Θ<33° or 57°<Θ<72° when the linewidth of the unit wires is greater than 3 μm.

Also, the angle (Θ, Θ=|Θ₁|=|Θ₂|) formed by each of two unit wires andthe x-axis or the y-axis may satisfy 12°<Θ<78° when the line width ofthe unit wires is greater than 1 μm and not greater than 3 μm.

In addition, the angle (Θ, Θ=|Θ₁|=|Θ₂|) formed by each of two unit wiresand the x-axis or the y-axis may satisfy 0°≤Θ≤90° when the line width ofthe unit wires is not greater than 1 μm.

The unit mesh may consist of unit wires having the same size.

Also, the unit mesh may consist of two or more symmetrical unit wireshaving different sizes with each other.

The electrode patterns may comprise a first unit mesh and a second unitmesh having different sizes with each other.

According to another aspect of the present invention, there is provideda method for fabricating a touch sensor panel, comprising: forming ametal layer on a substrate; and bringing the metal layer into patterningto form electrode patterns in which continuous unit meshes consisting ofconductive unit wires are arranged, wherein two unit wires connected toa vertex of the unit mesh form an angle satisfying the followingequation with the x-axis or the y-axis:|Θ₁|=|Θ₂|

wherein,

Θ₁ is an angle formed by any one of two unit wires and the x-axis, and

Θ₂ is an angle formed by the other unit wire and the x-axis or they-axis.

The above equation is applied for all vertices constituting the unitmesh.

The angle (Θ, Θ=|Θ₁|=|Θ₂|) formed by each of two unit wires and thex-axis or the y-axis may satisfy 18°<Θ<33° or 57°<Θ<72° when the linewidth of the unit wires is greater than 3 μm.

Also, the angle (Θ, Θ=|Θ₁|=|Θ₂|) formed by each of two unit wires andthe x-axis or the y-axis may satisfy 12°<Θ<78° when the line width ofthe unit wires is greater than 1 μm and not greater than 3 μm.

In addition, the angle (Θ, Θ=|Θ₁|=|Θ₂|) formed by each of two unit wiresand the x-axis or the y-axis may satisfy 0°≤Θ≤90° when the line width ofthe unit wires is not greater than 1 μm.

Advantageous Effects

The touch sensor panel and the fabrication method thereof according tothe present invention have effects as follows.

First, metal wires for forming a metal mesh can be patterned so thatthey have symmetrical components being in correlation with each other onthe basis of x and y axes, thereby improving visibility.

Second, metal wires for forming a unit mesh can be patterned so thatthey have a combination of several symmetrical components being incorrelation with each other on the basis of x and y axes, therebyeffectively preventing the occurrence of a moire pattern. Third, thepatterning may be carried out so that several symmetrical components arecombined to form tetragonal to polygonal patterns freely according toangles, thereby improving visibility without limitation to patternforms.

Fourth, metal wires can have different angles formed by one of them andthe x or y axis, based on their line width greater or less than thereference line width value, thereby forming a metal mesh having anoptimum angle capable of preventing the occurrence of a moire pattern.

DESCRIPTION OF DRAWINGS

FIG. 1 is a configuration view showing an example of a unit meshaccording to the present invention.

FIG. 2 is a configuration view showing symmetrical components being incorrelation with each other on the basis of x and y axes.

FIGS. 3a to 3e are configuration views of the touch sensor panelsaccording to embodiments of the present invention.

FIGS. 4a and 4b show the configuration of a touch sensor panel patternedso that several symmetrical components are combined in a unit mesh.

FIGS. 5a to 5v are sectional views of a process for fabricating thetouch sensor panel according to the present invention.

MODE FOR INVENTION

Hereinafter, preferred embodiments of a touch sensor panel and afabrication method thereof according to the present invention will bedescribed as follows.

Features and advantages of the touch sensor panel and the fabricationmethod thereof according to the present invention will be apparentthrough the following detailed descriptions of embodiments.

FIG. 1 is a configuration view showing an example of a unit meshaccording to the present invention. FIG. 2 is a configuration viewshowing symmetrical components being in correlation with each other onthe basis of x and y axes.

In the present invention, metal wires for forming a metal mesh aresubject to patterning to have symmetrical components being incorrelation with each other on the basis of x and y axes, therebyimproving visibility.

In one embodiment of the present invention, metal wires for forming ametal mesh may be subject to patterning to have a combination of severalsymmetrical components being in correlation with each other on the basisof x and y axes in a unit mesh.

Also, the patterning may be carried out so that several symmetricalcomponents are combined to form tetragonal to polygonal patterns freelyaccording to angles, and the metal wires may form different angles withthe x or y axis, based on their line width greater or less than thereference line width value, thereby forming a metal mesh having anoptimum angle capable of preventing the occurrence of a moire pattern.

FIG. 1 is a configuration view of a unit mesh and unit wires accordingto the present invention. As used herein, the unit mesh refers to a meshpattern formed by crossing of a metal wire and another metal wire, andthe unit wire refers to a metal wire that corresponds to the length of aside constituting the unit mesh.

Also, the metal mesh consists of the connected unit meshes.

FIG. 2 shows symmetrical components being in correlation with each otheron the basis of x and y axes. In the touch sensor panel having electrodepatterns in which continuous unit meshes consisting of conductive unitwires are arranged, two unit wires connected to a vertex of the unitmesh form an angle satisfying the following equation with the x-axis orthe y-axis:|Θ₁|=|Θ₂|

wherein,

Θ₁ is an angle formed by any one of two unit wires and the x-axis, and

Θ₂ is an angle formed by the other unit wire and the x-axis or they-axis.

That is, a first unit wire 22 forms an angle Θ₁ with x-axis 20, and asecond unit wire 23 crossing with the first unit wire forms an angle Θ₂with x-axis 20 or y-axis 21.

The angles Θ₁ and Θ₂ are symmetrical components. Also, the aboveequation is applied for all vertices constituting the unit mesh.

As the symmetrical components, Θ₁ is a torsional angle of any one of twounit wires from the x-axis, and Θ₂ is a torsional angle of the otherunit wire from the x-axis or the y-axis, the angles Θ₁ and Θ₂ have thesame size.

Also, the x-axis is the direction of a driving electrode (T_(x))constituting the touch panel and the y-axis is the direction of adetecting electrode (R_(x)).

The size of the symmetrical components may vary depending on the linewidth of the unit wire, and it is preferably adopted based on the linewidth to form a metal mesh.

For example, the angle (Θ, Θ=|Θ₁|=|Θ₂|) formed by each of two unit wiresand the x-axis or the y-axis may satisfy 18°<Θ<33° or 57°<Θ<72° when theline width of the unit wires is greater than 3 μm.

Also, the angle (Θ, Θ=|Θ₁|=|Θ₂|) formed by each of two unit wires andthe x-axis or the y-axis may satisfy 12°<Θ<78° when the line width ofthe unit wires is greater than 1 μm and not greater than 3 μm.

In addition, the angle (Θ, Θ=|Θ₁|=|Θ₂|) formed by each of two unit wiresand the x-axis or the y-axis may satisfy 0°≤Θ≤90° when the line width ofthe unit wires is not greater than 1 μm.

When the size of the symmetrical components satisfies such range, theoccurrence of a moire pattern can be prevented.

FIGS. 3a to 3d show that the unit mesh consisting of a unit wire andanother unit wire crossing with the unit wire has symmetrical componentshaving the same size.

The unit mesh according to the present invention is not limited to theforms shown in FIGS. 3a to 3d and may be modified and embodied in otherforms.

FIG. 3e shows the configuration of a metal wire consisting of the unitmesh of FIG. 3 d.

Thus, the symmetrical components of the unit mesh may have the samesize. Alternatively, several symmetrical components may be combined inthe unit mesh through patterning.

FIGS. 4a and 4b show the configuration of a touch sensor panel patternedso that several symmetrical components are combined in a unit mesh.

As shown in FIG. 4a , a unit mesh consisting of a unit wire and anotherunit wire crossing with the unit wire may be configured to have acombination of first and second symmetrical components having differentsizes with each other.

In FIG. 4a that shows symmetrical components being in correlation witheach other on the basis of x and y axes, a first unit wire 42 forms anangle Θ₁ with x-axis 40, a second unit wire 43 crossing with the firstunit wire forms an angle Θ₂ with x-axis 40 or y-axis 41, a third unitwire 44 connected to the first unit wire 42 forms an angle Θ₃ withx-axis 40, and a fourth unit wire 45 connected to the second wire 43forms an angle Θ₄ with x-axis 40 or y-axis 41.

The angles Θ₁ and Θ₂ have the same size and the angles Θ₃ and Θ₄ havethe same size, but the first symmetrical components (Θ₁, Θ₂) have a sizedifferent from the second symmetrical components (Θ₃, Θ₄).

Thus, the first symmetrical regions having angles Θ₁ and Θ₂ with the xand y axes and the second symmetrical regions having angles Θ₃ and Θ₄with the x and y axes are combined to form a unit mesh.

FIG. 4b shows the configuration of a metal wire formed by combination ofa structure of the unit mesh in which symmetrical components have thesame size as shown in FIG. 3a and a structure of the unit mesh in whichthe first symmetrical regions having angles Θ₁ and Θ₂ with the x and yaxes are combined with the second symmetrical regions having angles Θ₃and Θ₄ with the x and y axes as shown in FIG. 4 a.

That is, the metal wire is formed by combination of a first unit meshconsisting of symmetrical components having the same size and a secondunit mesh consisting of a first symmetrical component and a secondsymmetrical component having different sizes.

Such metal mesh-forming metal wires are subject to patterning to havesymmetrical components Θ₁, Θ₂ being in correlation with each other onthe basis of x and y axes, thereby fabricating a touch sensor panelhaving improved visibility, as described below.

FIGS. 5a to 5v are sectional views of a process for fabricating thetouch sensor panel according to the present invention.

The fabricating process in the following description shows an example ofa process to which the unit mesh according to the present invention isapplied. The process of the present invention is not limited to thestructures and process conditions described below, and variousmodifications may be adopted.

First, as shown in FIG. 5a , a first oxide layer 51 and a first metallayer 52 are formed on a transparent substrate 50.

The first oxide layer 51 may include indium tin oxide (ITO) and indiumzinc oxide (IZO). The first metal layer 52 may include a Mo and Agalloy, an Al alloy, and the like.

Thereafter, a photoresist 53 is applied on the first metal layer 52 asshown in FIG. 5b , and then exposed using a photomask 54 in which a meshpattern is formed as shown in FIG. 5 c.

Subsequently, as shown in FIG. 5d , a photoresist pattern layer 53 a isformed by developing the photoresist 53. As shown in FIG. 5e , the firstmetal layer 52 and the first oxide layer 51 are selectively patternedwith a wet etching liquid by using the photoresist pattern layer 53 a,thereby forming a first oxide layer pattern 51 a and a first metalpattern 52 a.

Here, the first metal pattern 52 a becomes a metal wire in any onedirection, which constitutes the detecting unit. Metal wires consistingof continuous unit wires may be patterned so that a unit wire andanother unit wire crossing with the unit wire have symmetricalcomponents being in correlation with each other, as shown in FIGS. 2 and4 a.

In the touch sensor panel having electrode patterns in which continuousunit meshes consisting of conductive unit wires are arranged, thesymmetrical components obtained in the patterning for forming the firstmetal pattern 52 a means that two unit wires connected to a vertex ofthe unit mesh form an angle satisfying the following equation with thex-axis or the y-axis:|Θ₁|=|Θ₂|

wherein,

Θ₁ is an angle formed by any one of two unit wires and the x-axis, and

Θ₂ is an angle formed by the other unit wire and the x-axis or they-axis.

Also, in the patterning for forming the first metal pattern 52 a, twounit wires are patterned so that the angle (Θ, Θ=|Θ₁|=|Θ₂|) formed byeach of two unit wires and the x-axis or the y-axis satisfies 18°<Θ<33°or 57°<Θ<72° when the line width of the unit wires is greater than 3 μm,the angle satisfies 12°<Θ<78° when the line width of the unit wires isgreater than 1 μm and not greater than 3 μm, and the angle satisfies0°≤Θ≤90° when the line width of the unit wires is not greater than 1 μm.

Thereafter, as shown in FIG. 5f , the photoresist pattern layer 53 a isremoved and an insulating layer (SiON) 55 is formed on the first metalpattern 52 a.

Subsequently, a photoresist (PR) 56 is applied on the insulating layer55 as shown in FIG. 5g . The photoresist 56 is then exposed using aphotomask 57 in which a hole pattern is formed as shown in FIG. 5h ,thereby forming a photoresist pattern layer 56 a as shown in FIG. 5 i.

Thereafter, as shown in FIG. 5j , the insulating layer 55 is selectivelyremoved through a dry etching process using the photoresist patternlayer 56 a, thereby forming a connection hole 57. As shown in FIG. 5k ,the photoresist pattern layer 56 a is removed.

Subsequently, as shown in FIG. 5l , a second oxide layer 58 and a secondmetal layer 59 are formed on an insulating layer pattern 55 a in whichthe connection hole 57 is formed.

Thereafter, as shown in FIG. 5m , a photoresist 60 is applied on thesecond metal layer 59. As shown in FIG. 5n , the photoresist 60 isexposed using a photomask 61 in which a mesh bridge pattern is formed.

Subsequently, as shown in FIG. 5o , a photoresist pattern layer 60 a isformed by developing the photoresist 60. As shown in FIG. 5p , thesecond metal layer 59 and the second oxide layer 58 are selectivelypatterned with a wet etching liquid by using the photoresist patternlayer 60 a, thereby forming a second oxide layer pattern 58 a and a meshbridge pattern 59 a.

Thereafter, as shown in FIGS. 5q to 5v , an inorganic or organicinsulating layer 62 is formed on the mesh bridge pattern 59 a, and aphotoresist pattern layer 63 a and an inorganic or organic insulatinglayer pattern layer 62 a are formed by performing application of aphotoresist 63 and exposure and development using a photomask 64,thereby fabricating a substrate on which detecting electrodes anddriving electrodes are formed.

The touch sensor panel according to the present invention thusfabricated has moire suppression characteristics as follows.

TABLE 1 Metal Line Angle Width 0 3 12 18 27 33 42 48 57 63 72 78 87 90 5Strong Strong Strong Weak No Weak Weak Weak Weak No Weak Strong StrongStrong 4 Strong Strong Medium Weak No Weak Weak Weak Weak No Weak MediumStrong Strong 3 Medium Medium Weak No No No No No No No No Weak MediumMedium 2 Medium Medium Weak No No No No No No No No Weak Medium Medium 1No No No No No No No No No No No No No No

Table 1 shows the degree of a moire pattern occurred according to theline width of unit wires and an angle formed by each of two unit wiresand the x-axis or the y-axis.

It is preferred that the moire pattern occurred is observed depending onpixel structures and liquid crystal types.

The pixel structures may be divided into RGB Stripe, Pentile, S-Stripeand Diamond, and the liquid crystal types may be divided into LCD andOLED. Applying such division, moiré characteristics on an angle size arecompared at 1, 2, 3, 4 and 5 μm, the line width of metal wires.

In the pixel structures, the RGB Stripe form is obtained by arrangingthree sub-pixels of R, G and B with the same area, the Pentile form isobtained by making the size of the G sub-pixel be decreased, e.g.,making the size of sub-pixels into R:G:B=2:1:2, or by making a unitpixel in the form of RGBG, considering that the human eye is sensitiveto green color.

Also, the S-Stripe form is obtained by arranging blue organicsvertically while arranging green and red organics horizontally, and theDiamond form is obtained by adopting a diamond-type pixel arrangementthat disposes sub-pixels diagonally while maintaining the RGBG Pentilestructure, so as to enhance readability.

Thus, by comparison of moiré characteristics depending on RGB Stripe,Pentile, S-Stripe and Diamond pixel structures since the readability maybe different according to such pixel structures, the moirécharacteristics can be accurately confirmed and the effect obtained fromthe size of the symmetrical components according to the presentinvention can be confirmed.

That is, for each back light source of red, green, blue and white, thetouch panel fabricated by the method according to the present inventionis disposed on the top of an image display device (divided by the liquidcrystal types of LCD, OLED and pixel structures), and then is observedfor its moiré pattern on angles formed by rotation. The degree of moirépattern is evaluated by levels of strong, medium, weak and no occurrenceon angles of an inner unit wire.

The moiré pattern is confirmed to occur into the order ofgreen>white>red=blue for back light sources. Therefore, a test forevaluating moiré pattern occurrence is conducted for the green sourcethat causes the strongest moiré pattern occurrence.

Also, the moiré pattern is analyzed according to the angle size ofsymmetrical components. When calculating the angle size of symmetricalcomponents, it is confirmed that the less moiré pattern occurs from thethinner line width.

Thus, according to the present invention, the angle (Θ, Θ=|Θ₁|=|Θ₂|)formed by each of two unit wires and the x-axis or the y-axis maysatisfy 18°<Θ<33° or 57°<Θ<72° when the line width of the unit wires isgreater than 3 μm, the angle may satisfy 12°<Θ<78° when the line widthof the unit wires is greater than 1 μm and not greater than 3 μm, andthe angle may satisfy 0°≤Θ≤90° when the line width of the unit wires isnot greater than 1 μm.

The touch sensor panel of the present invention and the fabricationmethod thereof as mentioned above allow metal wires for forming a metalmesh to be patterned so that they have symmetrical components being incorrelation with each other on the basis of x and y axes, therebyimproving visibility.

Also, the patterning is carried out so that several symmetricalcomponents are combined to form tetragonal to polygonal patterns freelyaccording to angles, and metal wires have different angles formed by oneof them and the x or y axis, based on their line width greater or lessthan the reference line width value, thereby forming a metal mesh havingan optimum angle capable of preventing the occurrence of a moirepattern.

Although the present invention has been described in connection with thepreferred embodiments, the embodiments of the present invention are onlyfor illustrative purposes and should not be construed as limiting thescope of the present invention.

It will be understood by those skilled in the art that various changesand modifications can be made thereto within the technical spirit andscope defined by the appended claims.

[EXPLANATION OF REFERENCE NUMERALS] 20: X-axis 21: Y-axis 22: First unitwire 23: Second unit wire

The invention claimed is:
 1. A touch sensor panel having electrodepatterns in which continuous unit meshes consisting of conductive unitwires are arranged, wherein two conductive unit wires, connected to avertex of the respective unit mesh, form an angle satisfying thefollowing equation with an x-axis or a y-axis:|Θ₁|=|Θ₂| wherein Θ₁ is an angle formed by any one of the two conductiveunit wires and the x-axis, and Θ₂ is an angle formed by the otherconductive unit wire and the x-axis or the y-axis, wherein therespective unit mesh consists of two or more symmetrical conductive unitwires having different sizes from each other, and one conductive unitwire and the other conductive unit wire crossing with the one conductiveunit wire are configured to have a combination of first and secondsymmetrical components having different sizes from each other.
 2. Thetouch sensor panel of claim 1, wherein the equation is applied for allvertices constituting the respective unit mesh.
 3. The touch sensorpanel of claim 1, wherein the angle (Θ, Θ=|Θ₁|=|Θ₂|) formed by each ofthe two conductive unit wires and the x-axis or the y-axis satisfies18°<Θ<33° or 57°<Θ<72° when the line width of the conductive unit wiresis greater than 3 μm.
 4. The touch sensor panel of claim 1, wherein thefirst and second symmetrical components are in correlation with eachother on the basis of x and y axes, a first conductive unit wire forms afirst angle with x-axis, a second conductive unit wire crossing with thefirst conductive unit wire forms a second angle with x-axis or y-axis, athird conductive unit wire connected to the first conductive unit wireforms a third angle with x-axis, and a fourth conductive unit wireconnected to the second conductive wire forms a fourth angle with x-axisor y-axis, and the first and second angles have a same size and thethird and fourth angles have a same size, but the first symmetricalcomponents with the first and second angles have a size different fromthe second symmetrical components with the third and fourth angles.